Approximately 25,000 American troops are based in the most populous part of Okinawa. The US has offered to move them to a quieter area, but the Okinawans want them gone, and they have elected a Governor who has promised to get rid of them. The usefulness of this base and its many troops, dependents, and civilian hangers-on is questionable even as North Korea flexes its muscles.
http://www.nytimes.com/2010/11/29/world/asia/29okinawa.html?_r=1&ref=world





